Conventionally, an image forming apparatus typically has an input display panel (hereinafter referred to as an operation panel) which is connected thereto and integrated therewith. There is also a printing apparatus having a console unit which is detachably attached to the main body thereof (for example, Japanese Patent Laid-Open No. 2001-67201). In a printing apparatus which includes a reader unit and an engine unit in the main body thereof, the operation panel may be detachably attached to the main body and send an operate instruction to the reader unit and the engine unit separately. In recent years, there has been a compact computer device which includes a three-dimensional acceleration sensor or the like, and uses the sensor to detect an inclination of the device and changes the orientation of a document or an image displayed on a display unit of the computer device, depending on the inclination of the device.
In the aforementioned image forming apparatus having the removable operation panel, the user can change various settings while carrying the operation panel which has been removed from the main body. However, the operation panel can only be removed from the main body and operated. There is a desire to improve the operability by utilizing the portability of the operation panel.
In the compact computer device including the three-dimensional acceleration sensor, the display orientation is only changed using the output of the sensor. For example, the computer device provides a print instruction to a printer in a manner similar to that of conventional computer devices.